Fuse for high-tension electrical circuits.



L. N. BRIGHTON.

FUSEFOR HIGH TENSION ELECTRICAL cmcuns.

APPLICATION FILED JAN- 25. 1913- Patented Apr. 15,1919.

Fly.

Fig, 2

WITNESSES. a (1% tube would fall to the ground.

UNITED STATES PATENT OFFICE.

LESLIE N. CRICHTON, OF SALT LAKE CITY, UTAH, ASSIGNOR TO WESTINGHOUSE ELEC- TRIO AND MANUFACTURING COMPANY. A CORPORATION OF PENNSYLVANIA.

FUSE FOR HIGH-TENSION ELECTRICAL CIRCUITS.

Specification of Letters Patent.

Patented Apr. 15, 1919.

Application filed January 25, 1913. Serial No. 744,179.

To all IlltOl/t it may hit "WWI? Be it known that I, Lnsiin-z N. GRICHTON, a citizen of the United States, residi at Salt Lake City, in the county of Salt a-ke and State of Utah, have invented a. new and useful Fuse for High-'lension Electrical Circuits.

My invention relates to electrical fuses and especially to those used on high tension electrical circuits. It has for its object the production of a fuse for the purpose stated, which shall be ellicient and economical, which may be safely used out doors if desired. and which will be useful in any other location wheremoisture is present in the at mospherc to such an extent as to render useless ordinary expulsion fuses.

lt has been found by experience that entirely open fuses will not operate satisfactorily on relatively high voltages. hence for relatively high voltage circuits it has become general practice to inclose thefuse wire in an insulating tube which is strong enough to stand the high pressure due to the vaporizing of the fuse metal. Glass and porcelain have been found to be unsatisfactory for such service, so tubes made of fibrous materials are usually used. Such tubes are un satisfactory for outdoor use because they become slightly conducting when they are wet. so that in case the fuse inside the tube should blow, the currentwill still leak into the circuit beyond the fuse. This usually causes an arc to form on the outside of the tube. It has therefore been customary to rigidly fasten each end of the fuse wire with the tube slipped over the wire. and supported by itin such a. way that. when the fuse blew the However, such a scheme precludes the ll. of small fuses. because of their mechanical weakness and even large fuses are frequently broken out by heavy winds.

In order to overcome these (.ll ll(l\'ilt1ltl,.{0$ and in so doing to attain my objects above stated, I inclose. my fuse. wire for a part. or its length between terminals within a protecting tube or tubes. supported upon one or more insulators indepemlently of the fuse wire. When the fuse l)low the length of fuse wire which is outside of the inclos-ure is destroyed and the inclosure itself may be. partly destroyed. but in either case a gap is formed which cannot be bridged by moisture and across which a permanent arc cannot be maintained.

Figures 1 and 2 show in elevation two forms of my invention.

Referring to Fig. 1; 1 is a piece of flexible tubing fastened to a couple of metal insulator caps 2, 3 by means of the screws l, i, 4, 4. The metal caps may be fastened to the insulators 11 and 12 by cement, tie wires, or other methods. The. flexible tube I prefer to be of the kind which is commonly used by electricians and which consists largely of cotton fabric wo en on a circular loom.

()ne of the lincwires 5 is fastened to the insulator cap 23. The other line wire 6 is fastened to an insulator T. The fuse wire 8 is threaded through the tube and each end ftlr-l0lltul to the line wires 5 and (3. This fuse is preferably composed of some non-corrosive wire such as tinned copper.

The action of the fuse is as follows:

When the fuse melts an arc is formed inside the tube which ln explosively blown out in a very short interval of time. The short length of fuse which is outside the tube and between the insulator cap 2 and the ,line wire 6 is also destroyed. The result is that there is left a gap in the circuit so that no leakage can occur no matter how Wet the tube may be. The length of the gap between 2 and 6 should of course be greater than th sparking distance of the circuit voltage.

Fig. 2 shows another form of my invention which might be more economical because it eliminates one of the insulators shown in Fig. 1. It is also. more likely to be applicable to extremely high voltages because it has two tubes in series. The arrangement shown in Fig. '2 differs from that in Fig. l in thattwo rigid insulating tubes 9 and 10 are substituted for the flexible tube 1. In this case the blowing of the fuse causes a gap to occur between the tubes 9 and 10. One advantage of such an arrangement is that in case the section of fuse wire which is across the gap does not melt when the sections inside the tubes blow, it will. of its own weight. fall clear of the tubes.

My invention can of course be applied to other types of insulators and can be varied in numerous other ways. Besides being useful for outdoor operation. my invention is useful in any location where an ordinary expulsion fuse liable to be rendered uselOt) less by a deposit of moisture or other conducting material. I r

I claim as my invention:

1. A fuse comprising a pair of tenninals, a pair of insulators supporting the same, a pair of expulsion tubes supported on the insulators but separated by an air gap and open to the air at both ends, and a fusible conductor secured to the terminals and pass- :ing through the expulsion tubes.

A fuse comprising two insulated terminals, two expulsion tubes open at both ends to the air and secured to the respective terminals, and' a fusible conductor secured to the terminals and extending through the expulsion tubes.

3. A fuse comprising two terminal members', two expulsion tubes open at both ends to the air, and a fusible conductor extending through the said tubes.

4. A fuse comprising terminals having a gap between them, a fusible element bridging the terminals, and expulsion tubular means open to the air at both ends sup: ported independently of the fusible element and inclosing the same for a portion of its length.

5. The combination with two insulators having fuse terminals thereon, of a fusible conductor connected between the terminals and a plurality of tubular members that are open at both ends to the air supported by the insulators and adapted to surround the fusible conductor, said tubular members being of such length that a gap is left between them to preclude reestablishment of an are due to leakage thereacross when the conductor is fused.

6. A fuse comprising terminals having'a gap therebetween, a fusible element bridging the terminals with a dip downward, and a pair of expulsion tubes, each supported rlgidly on an insulator, with their adjacent opposite portions of the fusibleelement, but

ends inclined downwardly toward each other but separated by a gap, said tubes inclosing leaving the same exposed in the gap.

7 A fuse comprising a pair of terminals, a pai of insulators supporting the same, a pa' of'expulsion tubes supported on said i sulators by their outer ends and dipping /downward with their inner ends approachpredetermined at both ends and separated a predetermined distance apart.

10. The combination with two insulators and a fusible conductbr operatively connected thereto and adapted to sag therebetween, of tubular members that are open to the air at both ends adapted to loosely surround the fusible conductor and to be supported by the insulators, said tubular members being disposed a predetermined distance apart. Q

11. The combination with a pair of con- (luctor terminals, of a fuse comprlslng a pan of insulating members independently sup-- ported, one upon each of said conductor terminals, one of said insulating members having an opening formedtherethrough directed toward the other insulating member, a fuse wire extending between sald insulating members and extending through said opening having its opposite ends connected tosaid conductor termmals.

12. A fuse comprising a pair of insulating members spaced apart, a pair of supporting members one for each of said insulating members, means whereby one of sald insulat= ing members is adpistable, toWard' and away from the other of said insulating members in the plane of a straight line extending between said supporting members, a fuse Wire extending between said insulating members, and means for connecting conductor terminals to opposite ends-of said fuse wire.

13. A fuse comprising a pair of insulating members spaced apart means whereb one of said insulating members is adjustabfe relatively to the other of said insulating members, a fuse wire extending between said insulating members, one of said insulating members having an opening therethrough through which an intermediate portion of said fuse wire extends, and means for connecting conductor terminals to opposite ends of sald fuse wire.

- 14. A fuse comprising a pair of conductor members spaced apart and intended to be protected, an elongated insulating member having a tube-like aperture longitudinally therethrough. said insulating member being interposed in the ath of a line extending between said mem ers to be protected so that the aperture thereof extends transverse to such line, and a fuse wire extending from one of the members to be protected to one end of the insulating member and continuing through the aperture of the insulating member and from th opposite end of the insulating member to the second member to be protected.

15. A fuse comprising a pair of conductor members spaced apart and intended to be protected, and a. pair of elongated insulating members each having a tube-like aperture longitudinally therethrou h, said insulating members being interposed line extending between said members to be protected so that the apertures of said members extend transverse to such line, and a fuse wire extending from one of the members to be protected to one end of one of said insulating members thence through the aperture of said insulating member to the 0pin the path of a T new members being interposed in the pathoi a lin extending between said members to be protected so that the apertures of said memhers extend transverse to such line, a fuse wire extending from one of the members to be protected to ne end of one of said insulating members thence through the aperture of said insulating member to the op- J posite end thereof thence to one end of the second insulating member and through said second insulating member continuing out or" the second end of said second insulating member to the second member to be protected, and said insulating members being arranged in inclined relation to each other so that the apertures thereof at the ends of the insulating members adjacent the mem hers to be protected are farther spaced apart than the remaining ends of the insulating members, for the purpose described.

In testimony whereof, I have subscribed my name this 20th day of January, 1913.

LESLIE N. CRICHTON. Witnesses L. M. PHABIS, W. S.'JENNENS. 

